Exploring the optical behaviour of a Type Iax supernova SN 2014dt

Abstract

We present optical photometric (up to ∼ 410 d since B max ) and spectroscopic (up to ∼ 157 d since B max ) observations of a Type Iax supernova (SN) 2014dt located in M61. SN 2014dt is one of the brightest and closest ( D ∼ 20 Mpc) discovered Type Iax SN. It best matches the light-curve evolution of SN 2005hk and reaches a peak magnitude of M B ∼− 18.13 ± 0.04 mag with

m 15 ∼ 1.35 ± 0.06 mag. The early spectra of SN 2014dt are similar to other Type Iax SNe, whereas the nebular spectrum at 157 d is dominated by narrow emission features with less blending as compared to SNe 2008ge and 2012Z. The ejecta velocities are between 5000 and 1000 km s − 1 , which also confirms the low-energy budget of Type Iax SN 2014dt compared to normal Type Ia SNe. Using the peak bolometric luminosity of SN 2005hk, we estimate the 56 Ni mass of ∼ 0.14 M

. The striking similarity between SN 2014dt and SN 2005hk implies that a comparable amount of 56 Ni would have been synthesized in the explosion of SN 2014dt.